| AVS 60th International Symposium and Exhibition | |
| Electronic Materials and Processing | Friday Sessions |
| Session EM+NS+SS+TF-FrM |
| Session: | Growth and Characterization of Group III-Nitride Materials |
| Presenter: | I.T. Ferguson, University of North Carolina at Charlotte |
| Authors: | B. Kuckgok, University of North Carolina at Charlotte B. Wang, University of North Carolina at Charlotte M. Orocz, University of North Carolina at Charlotte A.G. Melton, University of North Carolina at Charlotte N. Lu, University of North Carolina at Charlotte I.T. Ferguson, University of North Carolina at Charlotte |
| Correspondent: | Click to Email |
The ternary group III-Nitrides have demonstrated great promise in becoming the universal III-V compound semiconductor material for electronic, optoelectronic and other applications. This talk will show that the III-Nitrides can provide a possible solution for many applications that traditionally used III-V materials and associated devices. The development of wide-band gap compound semiconductors materials and devices, in particularly III-Nitrides, are leading a revolution in energy related areas of light emitting diodes (LEDs) and, more recently, solar cells and thermoelectric applications. However, a sound understanding of the appropriate material properties of III-Nitride for these diverse applications is needed as well as the understanding the compromises that are needed in the corresponding device structures. For example, the use of LEDs in general illumination, known as solid state lighting, incorporate InGaN in such a way that it shows large compositional fluctuations in the active region of the device. This physical phenomenon has been associated with bright emission from these devices despite the high defect density in the material. Moreover, these first generation devices typically have poor color rendering capability, in addition to poor correlated color temperature associated with gaps in the power spectrum. The group III-Nitride technology is also the basis for the development of a new generation of highly efficient solar cells. Wide-band gap InGaN is one of the few materials that can provide bandgaps in the 2.4-2.9 eV range for multi-junction photovoltaics devices to achieve efficiencies greater than 50%. Single phase InGaN with indium compositions up to 30% (2.5 eV band gap) are needed for these applications including understanding their absorption characteristics and ability to p-type dope. Another emerging application for the group III-Nitrides is high temperature (>700oC) thermoelectric applications for waste heat harvesting. Recent measurements of the thermoelectric properties of InGaN; including the Seebeck coefficient, the electrical conductivity, and the power factor, etc., show promising results for this application. However, the effects of point and extended defects on thermoelectric properties, in particularly the Seebeck coefficient, are not well understood and need further investigation.